The present invention relates to a new and improved construction of forced-flow boiler installation comprising a series connection of a feed pump, an economizer, an evaporator, and a water separator as well as a recirculation line or system having arranged therein a circulation pump and leading from the water outlet of the separator to the evaporator inlet. The invention further relates to a novel method of placing into operation such forced-flow-type boiler installation.
With such type boiler installations, especially if the boiler is designed in a tower type construction, so that the economizer is located geodetically high in relation to the evaporator, there results the problem that upon hot shutdown of the boiler the water in the economizer vaporizes, and thus, during rapid restarting by infeeding cold feed water into the still hot economizer there arises spontaneous condensation which is associated with pronounced pounding or impacts.
To reduce such pounding it is conventional to wait with the restarting of the boiler until the economizer has efficiently cooled. To shorten the cooling times the boiler can be vented. Due to these measures there is not only consumed energy for the drive of the ventilator or fan, but furthermore heat is lost to the surroundings.